GEO 101 Lecture Notes - Lecture 10: Monocline, Alpine Orogeny, Orogeny
2 May 2017
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Document Summary
Orogen (orogenic belt)- a linear range of mountains. About a dozen globally, numerous smaller ones: orogeny- a mountain building event; may last tens of millions of years, various mountain ranges. Himalaya mountains- formed about 50 million years ago until present (still building) alpine orogeny. Rocky mountains- formed about 80-50 million years ago (laramide orogeny) Joints- naturally formed cracks (fractures) in rocks (movement does not occur) Faults- a fracture on which one body of rock slides past another. Folds- a bend or wrinkle of rock layers; folds form from a consequence of ductile deformation: deformation: Change in shape (distortion: strain- the change in shape of an object in response to deformation, stretching- rock becomes longer, shortening- rock becomes shorter, shear- rock becomes tilted with change in angular relationships, brittle vs. ductile deformation. Brittle deformation- the cracking and fracturing of a material subjected to stress (chemical bonds break)
